Fuel cell separator and power generation cell

Abstract

A first metal separator of a power generation cell includes an oxygen-containing gas supply passage extending through the first metal separator in a separator thickness direction, a passage bead formed around the oxygen-containing gas supply passage, and a plurality of tunnels protruding from a side wall of the passage bead and expanded in the separator thickness direction. The plurality of tunnels have the same shape in cross section of a root connected to the passage bead.

What is claimed is: 
     
       1. A fuel cell separator comprising:
 a fluid flow field configured to allow fluid of an oxygen-containing gas, a fuel gas, or a coolant to flow along an electrode surface; 
 a fluid passage connected to the fluid flow field and extending through the fuel cell separator in a separator thickness direction; and 
 a bead seal used for sealing, the bead seal being formed around the fluid passage and protruding in the separator thickness direction, 
 the fuel cell separator being stacked on a membrane electrode assembly, and a compression load being applied to the fuel cell separator in a stacking direction, 
 wherein a plurality of tunnels protrude from a side wall of the bead seal, and are expanded in the separator thickness direction, 
 the plurality of tunnels have same shape in cross section of a root connected to the bead seal, 
 wherein the plurality of tunnels include a plurality of inner tunnels protruding from an inner side wall of the bead seal and a plurality of outer tunnels protruding from an outer side wall of the bead seal; and 
 the plurality of inner tunnels and the plurality of outer tunnels are connected to the bead seal alternately. 
 
     
     
       2. The fuel cell separator according to  claim 1 , wherein each of the plurality of tunnels has a trapezoidal shape in cross section, and the plurality of tunnels have same bottom side length, same upper side length, and same height. 
     
     
       3. The fuel cell separator according to  claim 1 , wherein the
 the plurality of inner tunnels and the plurality of outer tunnels have same shape in cross section of a root connected to the bead seal. 
 
     
     
       4. The fuel cell separator according to  claim 1 , wherein another fuel cell separator is provided adjacent to the fuel cell separator; and
 the plurality of the tunnels of the fuel cell separator and a plurality of tunnels of the other fuel cell separator have same shape in cross section. 
 
     
     
       5. The fuel cell separator according to  claim 1 , wherein the plurality of tunnels have same width. 
     
     
       6. A power generation cell comprising a fuel cell separator and a membrane electrode assembly stacked on the fuel cell separator,
 the fuel cell separator comprising: 
 a fluid flow field configured to allow fluid of an oxygen-containing gas, a fuel gas, or a coolant to flow along an electrode surface; 
 a fluid passage connected to the fluid flow field and extending through the fuel cell separator in a separator thickness direction; and 
 a bead seal used for sealing, the bead seal being formed around the fluid passage and protruding in the separator thickness direction, 
 the fuel cell separator being stacked on the membrane electrode assembly, and a compression load being applied to the fuel cell separator in a stacking direction, 
 wherein the fuel cell separator includes a plurality of tunnels protruding from a side wall of the bead seal, and are expanded in the separator thickness direction, 
 the plurality of tunnels have same shape in cross section of a root connected to the bead seal, 
 wherein the plurality of tunnels include a plurality of inner tunnels protruding from an inner side wall of the bead seal and a plurality of outer tunnels protruding from an outer side wall of the bead seal; and 
 the plurality of inner tunnels and the plurality of outer tunnels are connected to the bead seal alternately.